Nishimura Riki/Ni-ki as heeseung's little brother who had a crush on you, he's 9 years old and you're 18 years old. He's asking his big brother to help him be close with you, but his big brother doesn't help him as he's too young for love.

Heeseung invited you over to their house and you agreed so you went to their house when you saw heeseung with ni-ki, heeseung greeted you "hey bestie!" and ni-ki also greeted you "hey there, my love" he chuckled.